1. Field of the Invention
The present invention relates to devices which detect, collect, weigh and count surgical sponges. The present invention also relates to surgical sponges which can be detected non-optically.
2. General Background of the Invention
During surgery absorbent sponges are used to soak up blood and other body fluids in and around the incision site. Because the risk of a sponge being retained inside a patient is so great, surgical personnel go to great lengths to account for each and every sponge which is used in surgery. Strict sponge count policies have been developed by hospitals to deal with this issue. Moreover, surgeons and anesthesiologists determine blood loss by using visual inspection or the manual weighing of soiled sponges, thus soiled sponges are usually kept in one area of the operating room. Another area of concern regarding soiled surgical sponges is the risk of transmission of bloodborne diseases such as hepatitis B virus (HBV) and human immunodeficiency virus (HIV). To reduce exposure and contamination every precaution necessary should be taken to reduce risk of infection.
Sponge counts are an essential part of operating room procedure. They help ensure patient safety by reducing the chance that a sponge will be retained inside of the patient. Typical sponge count policies include: an initial count at the beginning of a procedure and subsequent counts throughout the procedure when additional sponges are added to the sterile field, before the closure of a deep incision, after the closure of a body cavity, when scrub or circulating personnel are relieved, and before the procedure is completed.
In addition, it is necessary for the anesthesiologist and surgeon to have an accurate measurement of blood loss contained in sponges, so that if excessive blood loss is occurring, blood components can be ordered and administered immediately. This information is provided by weighing soiled sponges and then subtracting the dry weight of the number of sponges weighed from the total.
Moreover, soiled sponges are a source of contamination, thus handling and exposure should be kept to a minimum. Procedures which reduce the transmission of bloodborne pathogens include making sure that soiled sponges are handled with gloves and instruments only and that used soiled sponges are appropriately contained and confined.
In 1992, the Occupational Safety and Health Administration (OSHA) issued new regulations regarding bloodborne pathogens in U.S. hospitals. Nearly 6 million healthcare workers in the United States who could be "reasonably anticipated" to come in contact with blood and other body fluids are subject to the new regulations. These regulations are intended to reduce worker exposure to hepatitis B virus (HBV), human immunodeficiency virus (HIV), or other bloodborne pathogens. Under the section on Engineering and Work Practice Controls, hospitals are required to eliminate or minimize employee exposure. This includes the implementation of new designs for devices which count sutures and sponges.
For more information about surgical sponge handling and counting, please see U.S. Pat. No. 4,422,548, incorporated herein by reference.
U.S. Pat. No. 3,367,431 discloses a device for automatically counting and weighing surgical sponges. However, the device cannot distinguish between different sponges. Also, the amount of blood contained in soiled sponges must be manually calculated. Further, it does not use removable disposable bags.
U.S. Pat. No. 4,295,537 discloses a sponge-collecting device that keeps count and determines the weight of blood-soaked sponges. However, the device cannot automatically distinguish between different sponges. Also, the device does not automatically count the sponges (the number and dry weight of the sponges must be manually input).
U.S. Pat. No. 4,422,548 discloses a sponge-collecting device that determines the weight of blood-soaked sponges. However, the device cannot automatically distinguish between different types of sponges. It also cannot determine the amount of blood in the sponges.
U.S. Pat. No. 5,009,275 discloses a sponge-collecting device that determines the weight of blood-soaked sponges. However, the device cannot automatically distinguish between different types of sponges, and so it cannot automatically determine the amount of blood loss when sponges of different dry weights are collected in the container.
Radio Frequency Identification Systems are based on two principle components, a passive tag or transponder and a hand held or stationary reader. In operation, the hand held or stationary reader emits a low frequency magnetic field, which activates the passive tag or transponder within its range. The passive tag has no power source of its own. It derives the energy needed for operation from the magnetic field generated by the reader. Because the tags have no power source of their own, the only limitation to the operational lifespan of the tag is the durability of its protective encapsulation, usually, but not limited to, plastic or glass. Tags are available in many shapes and sizes, each designed for the unique rigors and requirements of specific applications. RF tags operate by proximity as opposed to optics like a bar code. As a result they can be read in harsh environments, submerged in liquids and can be read spherically from any direction, through most materials. They can be read through tissue, bone, etc.
Also of potential interest are the following U.S Pat. Nos.: 3,367,431; 4,193,405; 4,498,076; 4,510,489; 4,658,818; 4,922,922; 5,031,642; 5,057,095; 5,103,210; 5,188,126; 5,190,059; 5,300,120; 5,329,944; 5,353,011; 5,357,240; 5,381,137; all patents cited in the file of U.S. patent application Ser. No. 08/286,413.